Sometimes when I am feeling particularly frazzled or just need to see something beautiful, I jog (uphill-both ways) to the Piazzale Michelangelo at the crack of dawn. I haven't brought my camera with me in the morning (obviously-since running with a three pound DSLR is dangerous and just plain stupid), but I hike up there for sunset every once in awhile.
I ask you, how could you be mad/sad/upset at anything when this is the first or last thing you see during your day?
Florence is the most beautiful city I've ever laid eyes on; so far!